[PATCH v12 09/22] selftests/vm: fix alloc_random_pkey() to make it really random

From: Ram Pai
Date: Wed Feb 21 2018 - 21:00:41 EST


alloc_random_pkey() was allocating the same pkey every time.
Not all pkeys were geting tested. fixed it.

cc: Dave Hansen <dave.hansen@xxxxxxxxx>
cc: Florian Weimer <fweimer@xxxxxxxxxx>
Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
---
tools/testing/selftests/vm/protection_keys.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index aaf9f09..2e4b636 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -24,6 +24,7 @@
#define _GNU_SOURCE
#include <errno.h>
#include <linux/futex.h>
+#include <time.h>
#include <sys/time.h>
#include <sys/syscall.h>
#include <string.h>
@@ -602,13 +603,15 @@ int alloc_random_pkey(void)
int alloced_pkeys[NR_PKEYS];
int nr_alloced = 0;
int random_index;
+
memset(alloced_pkeys, 0, sizeof(alloced_pkeys));
+ srand((unsigned int)time(NULL));

/* allocate every possible key and make a note of which ones we got */
max_nr_pkey_allocs = NR_PKEYS;
- max_nr_pkey_allocs = 1;
for (i = 0; i < max_nr_pkey_allocs; i++) {
int new_pkey = alloc_pkey();
+
if (new_pkey < 0)
break;
alloced_pkeys[nr_alloced++] = new_pkey;
@@ -624,13 +627,14 @@ int alloc_random_pkey(void)
/* go through the allocated ones that we did not want and free them */
for (i = 0; i < nr_alloced; i++) {
int free_ret;
+
if (!alloced_pkeys[i])
continue;
free_ret = sys_pkey_free(alloced_pkeys[i]);
pkey_assert(!free_ret);
}
- dprintf1("%s()::%d, ret: %d pkey_reg: 0x%x shadow: 0x%x\n", __func__,
- __LINE__, ret, __rdpkey_reg(), shadow_pkey_reg);
+ dprintf1("%s()::%d, ret: %d pkey_reg: 0x%x shadow: 0x%016lx\n",
+ __func__, __LINE__, ret, __rdpkey_reg(), shadow_pkey_reg);
return ret;
}

--
1.7.1